I sometimes hesitate to call parents when I'm having a problem with one of my students. I feel guilty that I'm not able to solve it myself and don't want the parents to lose any confidence they may have about my ability to be an effective teacher.
Trying to do everything yourself is a feeling shared by many teachers. Unfortunately, the desire to Do It All can sometimes be counter-productive. By postponing the contact until things are almost out of control will actually created a bit of distrust from the folks at home. "Why didn't you tell us about this earlier?" is something they will either say or think. And if said, we're most likely to think, "Yeah. Why didn't I address this earlier?"
We call that a Lose/Lose situation.
Granted, I don't recommend that you call for the least little thing. It's just that notifying parents of an issue in a timely fashion can help to lay the foundation for future success.
How about a compromise?
Call the parents and let them know that there is a bit of problem. Let them also know that you are taking care of it right now. If, however, the problem does not get resolved to your liking, you'll be back in touch with them. You're merely calling now to give them a bit of a heads up.
A teacher who joined us during our discussion added this thought:
It's kind of like giving out a progress report before giving out report cards.
Yes, that's exactly what's it like. And I'm guessing the parents will appreciate the "behavior progress report" on two levels.
For one, most parents do like to be kept apprised of how their children are doing in class. (Assume this of all parents. The ones who don't want to know represent a small portion of the total number of parents with whom we work.) The timely phone contact will help to keep them in the loop.
For another, you will be making it clear that you are in charge in the room. That doesn't mean that there won't be any problems at all. It just means that you will be the one to deal with them initially but that you're not afraid to involve the parents if it should prove necessary.
Golden opportunity: Keep a contact log so that you can call the parents again to let them know that you were able to solve the problem. That would score you some big trust points.